A relay is an electrically controllable switch device that includes a mechanical switch and a coil configured to switch the mechanical switch. The relay can be actuated by driving a pull-in current through the coil. This current through the coil causes a magnetic field which, in turn, causes the mechanical switch to change its switching state (e.g., from an off-state to an on-state). In order to actuate the relay, the pull-in current is required to flow for a defined time period that allows establishment of a sufficient magnetic field. After the relay has been actuated, a current lower than the pull-in current is required to keep the relay in the actuated state.
Thus, a modern relay controller (relay driver) is configured to reduce the current through the coil from a pull-in level to a hold level lower than the pull-in level after a defined time period. This helps to reduce the power consumption of the relay controller.
There is a need to further reduce the power consumption involved in driving a relay, in particular in applications that include a plurality of relays.